Systems and methods are provided improving the join time of low energy devices in a time slotted channel hopping (TSCH) network. Utility companies, home automation providers, industrial automation providers, scientific and environmental application providers, and other resource providers may communicate with endpoints via devices operating on a TSCH network, defined by IEEE 802.15.4. Powered parent devices (e.g., electric meters, routers) are connected via a TSCH network, which is referred to as the primary network or the primary TSCH network (PN-TSCH). Powered parent devices are also referred to herein as parent nodes or TSCH nodes. To maintain synchronization, powered TSCH nodes communicate with each other and maintain synchronization with each other through the use of periodic beacons that are transmitted between TSCH nodes.
Low energy (LE) devices are used to monitor and/or manage consumption of resources (e.g., electricity, heat, water, other utilities, as well as other types of resources). In some aspects, LE devices can be Internet-Of-Things (IoT) enabled devices that can be used in smart power grid and smart home technologies. Low energy devices are utilized as endpoints in TSCH networks and communicate messages with A/C powered parent nodes. Low energy devices (also referred to as LE nodes, LE endpoints, LE endpoint nodes) include battery powered devices, energy harvesting devices, and vampire tapping devices. LE endpoints utilize a second, low energy hopping pattern in a secondary TSCH network. The secondary TSCH network utilized by the LE endpoints uses a channel hopping protocol in which channel frequencies switch at a much slower rate than the primary TSCH network used by the parent devices. The secondary TSCH network is referred to herein as an LE TSCH network. The slower channel hopping protocol utilized by the LE network is referred to as a low energy channel hopping protocol. To save on power consumption and conserve battery life, the LE-TSCH network allows LE devices to enter a sleep state (i.e. turning off higher powered electronics such as oscillators). Because LE devices are limited in the possible number of transmissions in a given TSCH slot frame, LE devices do not transmit or receive beacons from A/C powered parent nodes for regular synchronization. There is a need for a mechanism that allows for synchronization between parent TSCH nodes and battery powered LE devices.